Campaigners have vowed to continue fighting to save the ancestral home of Owain Glyndwr for future generations.
The site of Sycharth in Montgomeryshire, mid-Wales was the manorial home of the princes of Powys Fadog and the birthplace of Glyndwr, the last Welsh-born holder of the title Prince of Wales.
Glyndwr led the last rebellion against the English and Sycharth was burned to the ground in May 1403 by the English prince, Henry, during his uprising.
All that remain now of the former motte and bailey castle, which is located a few miles from the English-Welsh border, are the earthworks.
Campaigners were speaking out on Owain Glyndwr Day, which was being celebrated on September 16.
Artist Dan Llywelyn Hall, who unveiled an oil painting of Glyndwr at Sycharth, said: “It’s painfully ironic that the home of our last Prince of Wales and the founding father of the Senedd be so grossly neglected and left to an inevitable demise.
“Let’s hope current political will, can recognises the need to celebrate of a man who stood up to repression and the enduring underdog.”
The portrait measures 3ft tall and is entitled Owain Glyndwr – The Rightful Reclaim and will now be displayed at the Senedd.
Russell George, the Conservative MS for Montgomeryshire, said: “I was delighted to take part in the unveiling of Dan Llywelyn Hall’s painting and depiction of Owain Glyndwr.
“It is important to protect our heritage sites and ensure accessibility to these historical sites so the people of Wales can learn more about our Welsh history.”
Over 10,000 people signed a petition calling for Sycharth to be bought by the Welsh Government from the landowner.
It was debated in the Senedd on Wednesday and Jack Sargeant MS, chairman of the petitions committee, called for improved signage for the site and urged the Welsh Government to build a visitor centre nearby.
“Cymru is an increasingly confident nation,” he told Plenary.
“If we are to build on that confidence, then we need to understand and celebrate our history, whether that is the Chartists or what happened in the 1980s when the Tories decimated communities like mine in Alyn and Deeside, or, indeed, Owain Glyndwr.
“We as Welsh people must be able to understand better the events that shaped us.”
Dawn Bowden, deputy minister for arts, sport and tourism, said the site was in private ownership, had sitting lifetime tenants and was not for sale.
“There are other ways to provide for its protection, care and promotion so that this unique historic site can be appreciated and enjoyed, both today and by future generations,” she said.
“As a scheduled monument, the site is protected through legislation, and there is close partnership working between the owners of the site, the Llangedwyn estate, the tenant farmers, and Cadw, to provide for the conservation and maintenance of Sycharth’s physical remains.”
Senedd members agreed to note the motion.